Floor Heat Works But Defrost Does Not 2006 Gmc Sierra

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Floor heat works but defrost does not 2006 gmc sierra.

I have a similar problem. Loss of hvac system mode and or temperature control replace hvac control module 04 01 39 007 06 17 2004 models. Ac heater fan not responding to switch in 2007 sierra. All frontal vents and floor vents work fine and can be switched between without problems.

2006 gmc sierra w dual auto climate control. The temperature door diverts air over the evaporator for cool air or points the flow over the heater core for warm air. Stuck won t switch to defrost of floor. Gmc 2006 sierra 1500 2wd question.

On my 2006 gmc sierra the a c heater mode stays on vent even when changing the control to the floor or defrost positions. Also the highest fan speed does not work all other speeds are ok. Once defrost is selected the blower motor keeps spinning but the top vent won t open. Heat won t transfer from vent to floor when put on floor heat blows from defrost.

I ll try these remedies but just curious about a brake job ac connection. How do i replace it. The only issue arises when you go to put it to defrost. 2000 silverado 5 3 4x4 my hvac actuator mode valve does not work.

Used gmc sierra 1500. Retg mentions above that he has diagnostic charts. I have tried the pulling the fuses both under hood and left of dash but that did not fix my problem. 2006 gmc sierra 1500 4x4 heat or a c won t switch from dash vents.

Yesterday on way to brake shop it was working just fine. Fan only blows defrost won t change to floor or vent. 2006 dodge ram 1500. 2006 slt 4x4 no floor heat 2 answers.

I didn t notice anything on the way home i was still in 400 00 shock but today i noticed it. Heat cold works fine. The blend door diverts the airflow to the defroster vents in the upper dashboard the floor discharge for heat or the center vents for air conditioning. Carmakers have used this basic design for 100 years.

No output on dash face vents or defrost vents but floor works ok.